This invention pertains to lubricant oil compositions and processes that reduce the propensity for end gas knock in flame propagation engines.
Engine knock is a phenomenon that occurs in a flame propagation engine due to auto ignition of a portion of the fuel air mixture ahead of the propagating flame front. This auto ignition occurs very rapidly; possibly creating a detonation wave that traverses the end gas leading to the audible ping or knock. This phenomena limits performance in all flame propagation engines because it limits the intake manifold pressure, the engine compression ratio, and the spark advance, factors that all affect the engine performance, emissions, and efficiency. There is much research directed toward reducing knock. Compositions of fuels and lubricants and methods to prevent or reduce such knock in flame propagation engines are highly desirable.